Yangtse cave, Fengshan County, Guangxi, type locality for eight species of plant. The plant-bearing part of the cave is ca 170 m deep and 70 m wide (note the person for scale)

As part of my research on the nettle family, Urticaceae I became aware of plants growing in the entrance caverns of caves several years ago and for over a year now my collaborators at the Guangxi Institute of Botany, China lead by Professor Yigang Wei and I have been working on documenting the full diversity of this unusual flora. This lead us to think about whether these plants may have become adapted to life in caves, in particular the relatively constant climate and low light. Especially for species which grow amongst the lowest light levels at the back of caverns where they are growing in a fraction of the light they could be expected to receive in a forest. We therefore applied for a grant from the Guangxi Key Laboratory of Plant Conservation and Restoration Ecology in Karst Terrain, and the Foreign Experts Bureau to undertake some preliminary work to document the climate, light and photosynthesis of the plants in the caves.

Fu Longfei and Chen Xiaoqin taking photosynthesis measurements using an instrument called a handheld PAM which uses fluorescence to measure various aspects of photosynthesis.

We selected the Yangtse cave as we know the diversity of plants that grow there (ten species of nettle alone), we have three data-loggers recording temperature and humidity in it and it is close to a town where we can spend the night. It is also a spectacular and beautiful place to spend several days working. The aim of our work was to collect the data necessary to test the hypothesis that the plants growing within the entrance cavern of the Yangtse cave exhibit different photosynthetic performance than the same or congeneric species growing outside of the cave. To do this we randomly selected individuals of three species of nettle in the genus Elatostema, one species of Begonia and a species of fern at four different locations in the cave, the back, midway into the entrance cavern, at the entrance and outside of the cave. We also brought two species of Elatostema from the living collection at the Guangxi Institute of Botany to compare their photosynthesis performance with members of the same species that had grown up within the cave. This was to get some indication as to how plastic their response was.

Elatostema obscurinervium, one of 31 species known only from caves and recently collected from a cave in northern Vietnam.

Each plant was connected to a hand-held PAM chlorophyll fluorometer, an incredibly sensitive device that can measure several key outputs of photosynthetic reactions in the chloroplasts as they take place. By comparing our study plants to those growing outside of the cave and from the scientific literature we hope to see whether cave-dwelling plants differ from non-cave plants in some of those parameters, and whether those differences are dependent upon what kind of plant they are. These parameters include the efficiency of photosynthesis, that is how much of the light energy is harnessed by the photosynthetic reactions, how much is dissipated and how resilient the photosynthetic apparatus is to changing light intensity. If we find a difference between cave and non-cave dwelling plants then taken together these measurements can provide some indication of which group of photosynthetic reactions are leading to these differences.

Haiti is infamous for extensive deforestation, less tha 4% of its original forest cover remains, which in addition to threatening many of its endemic trees with extinction has also increased the destructive impact of natural disasters of which there have been several in the last couple of decades. Deforestation is widely recognized as a significant threat to the well-being and security of Haitians and as a consequence many projects have been set up to plant trees, some more successful than others. Probably the biggest challenge to reforestation is to ensure that the communities involved are engaged and that they feel that the benefits of protecting and looking after a tree outweigh the sacrifice involved in not converting it to charcoal for cooking. Charcoal is the main fuel in rural areas and demand for it is high, a small bucket costing up to US$2 leading people to burn cacti to produce it. One NGO which seems to have been successful in engaging rural communities to grow and protect useful tree species has been Sadhana Forest Haiti

5 litre containers of charcoal can be found at most local shops. Charcoal is produced from local trees and represents the main source of fuel for cooking and so essential.

One of the difficulties for NGOs reforesting in any country is access to the scientific information necessary to make choices about what is grown: will a species grow in the chosen sites? How quickly will it grow? Will local people recognise it as a species of value to be protected? Will it support livelihoods? Where can seed be obtained from? How does it germinate? Is it native? What is its conservation value? This information can be tricky to get hold of, especially in countries with little botanical capacity or knowledge repositories. Often the result is that the species selected are those for which seed can be obtained and that are very well known to be of livelihood value, normally non-native species such as avocado, mango, eucalyptus of little conservation or biodiversity value but highly recognizable. Some native and especially endemic species for which knowledge of livelihood value is likely to be restricted to older members of a community or a small number of botanists and whose propagation and germination requirements are less well known will be harder for NGOs to incorporate.

Sadhana’s community liaison officer, Nixon Casseus, discussing fruiting of a 4 year-old Brosimum alicastrum with the owner of a small-holding who has been looking after the tree

RBG Kew has been working in neighboring Dominincan Republic for several years and has developed a strong relationship with the Dr. Rafael Moscoso National Botanical Garden, an institution with an active botanical community and seed bank. This represents an opportunity to share some of the knowledge and expertise on additional potential native plants with Sadhana Forest and the households that they work with. To this end I spent a few days visiting Sadhana Forest Haiti and some of the households. I was struck with the commitment and planning behind Sadhana Forest, who with few resources have provided several thousand seedlings to thousands of households in a region spanning Haiti’s south eastern border with the Dominican Republic. Hopefully, in collaboration with the Dr. Rafael Moscoso National Botanical Garden and Kew we will be able to introduce more native species of livelihood value to be planted in the future.

Carlos Magdalena of RBG Kew’s Department of Horticulture demonstrating the propagation of Brazil nut through cuttings

Paradoxically, forest-dependent rural communities in the tropics often have little experience of propagating trees, either from seed or from cuttings and this is the case in the Bolivian Amazon. As part of initiatives to enhance non-timber forest use through agroforestry and fruit tree production we sought the support of the innocent foundation to bring Kew horticulturalist, Carlos Magdalena to the Pando to provide hands-on training to three rural communities. Carlos is well known in Kew’s tropical nurseries as an expert in the propagation of challenging species, he is also a native Spanish-speaker and experienced in training. The aim of our training was to help communities propagate material of species for which they either can’t get enough seed e.g. Sinini (Annona muricata), whose seeds have low fertility such as acerola(Malpighia emarginata) or which take a year or more to germinate, such as the Brazil nut (Bertholletia excelsa).

A key requirement for cuttings to survive, even in a tropical climate is a polytunnel or sealed chamber to make sure that the leaves lose as little water as possible.

Training covered key aspects of making cuttings, air-layering and grafting. For example, how to cut the stem to expose the maximum amount of cambium, the tissue from which new roots will grow? What part of a stem is best for preparing a cutting? How many leaves should remain on a cutting? And how to trim them if necessary. It then covered how to look after cuttings once established, including how to make a polytunnel from locally available materials. In total we worked with approximately 60 community members spread over a 300 km stretch of the Pando. At each community the needs and interests were slightly different, as were the facilities available and so we tried to tailor the training accordingly. We found considerable interest and enthusiasm amongst community members, which suggests that the limited capacity for tree propagation is not for lack of interest.

A member of the Remanzo community preparing cuttings of acerola, a fruit for which there is high demand but which propagates very poorly from seed with germination rates of ca 2%

The Honorable Luis Gatty Ribeiro Roca, Mayor of Cobija (capital of the Pando) promoting the publication of our agroforest manual

The Darwin InitiativeForest Futures project aims to mitigate threats to natural forest in the Bolivian Amazon by raising awareness of the value of these forests, supporting the diversification of non-timber forest products and adapting a soil-restoring agroforest technique to the Amazon. The project was launched in 2013 and this week we held a half-day conference in the capital of the Pando, Cobija. The aim of which was to disseminate our results and outputs to local decision makers who included the Vicegovernor of the Pando, Dra Paola Terrazas Justiniano, the Mayor of Cobija, Luis Gatty Ribeiro Roca, representatives of the Universidad Amazonica del Pando, the Autoridad Bosques y Tierra (Forest and Land Authority) several NGOs involved in rural development and journalists from five television stations and two radio stations. We had 73 people participate in the meeting which for us was a great success.

The aim of this was to highlight the value of natural forest, both as a source of ecosystem services on which the Pando and the region depend, but also as a source of potential products which can either be harvested directly (non timber forest products) or cultivated in agroforest systems. The idea being that the perceived value of forest increases making unsustainable alternatives such as pasture for cattle or as sites for slash-and-burn seem less economical. Juan-Fernando Reyes from Herencia presented his vision for an integrated forest-based economy and future for the Pando, Bente Klitgaard outlined how the relationships between Kew, Herencia and our rural partners had developed and Alejandro Araujo Murakami presented a summary of the plant diversity of the Pando, ca 3,000 species and how this translated into stored carbon. I presented an overview of how Inga based agroforestry could help restore the soils of abandoned slash-and-burn sites to productivity and support sustainable agriculture in the region. In addition, with 73 participants at the conference it was a good opportunity to launch our Inga agroforest manual and promote the forthcoming book on economically promising Amazonian fruit tree species.

Cover of our forthcoming book on economically promising Amazonian fruit tree species

First galley proof of our agroforest manual which is due for publication in September 2016

Since the start of our Forest Futures project I had been thinking about the best way to support the production of agroforests once we have left. We had committed to produce a manual but my initial thoughts were that this is a little old-fashioned and that an electronic publication formatted for mobile phones would be a good option. The reality, however, is that Bolivia has very poor internet access. Even in Cobija, the capital of the Pando, internet acesss is sporadic and poor. Once in the field it is only available at a few points along the main road . We therefore decided to opt for a printed manual, of the size that it will fit on a narrow shelf or somebody’s day pack and on high quality paper that will resist the high humidity of the tropics.

The next decision was how to best communicate to the people we working with. I believe that a majority text-based format would not be of great interest or very accessible for the communities we work with. I decided on an image-rich poster-like format. This was because posters remain a major communication tool by Government and NGOs in the region and so local people will be familiar with them, secondly I assumed that Governments and NGOs know what they are doing! Following this I had to think quite hard about content. Whilst the mechanics of establishing a plot are relatively straightforward to explain what has struck me working with rural people is that communicating the underlying principles of agroforestry as we practice it is very challenging.

Through our work with rural communities we realised that a lot of background knowledge needs to be communicated if people are to understand the point of agroforestry

This is in part because a lot of their knowledge on soils and and nutrient cycling is based on temperate systems, either in Europe or the Andes where soils are replenished by the action of frost or weathering of rock. Amazonian soils have been leached over millions of years and hold few nutrients for plants but this is not obvious looking at the lush dense forest growing on them. So not only do we need to explain that the soils are very poor but then explain how such rich forest grows on them. Similarly, it is less challenging for people living away from the Amazon to accept that cutting forest is not sustainable, but quite a different thing when it is your livelihood that depends on slash-and-burn and when you have always been surrounded by forest for as far as the eye can see and that this has been the case for as long as anyone can remember. The upshot of these considerations are a substantial introduction that attempts to explain all of the background and context whilst assuming little prior knowledge.

Working with Royal Botanic Gardens, Edinburgh student Jia Dong and plant anatomist Louis Ronse De Craene has resulted in some exciting and thought-provoking images of nettle flowers. The aim of our collaboration is to understand how nettle flowers develop and in the process work out what parts they have in common and which they don’t. The samples used were from living collections at Edinburgh and RBG Kew, together with my own collections in alcohol made over several years. The results are some beautiful and very informative scanning electron micrographs which show that the part of the female flower which recieves pollen (stigma) and conducts it to the egg (style) is characterised by two classes of hairs, one comprising defensive tusk-like hairs (above) and the other receptive tubular like hairs (above & below).

Stigma hairs at the tip of the ovary of Pilea grandifolia, a succulent herb from Jamaica. Stigma hairs in the nettle family are characterised by their rounded obtuse tips and cylindrical shape. Image by Jia Dong, RBG Edinburgh.

Tubular hairs associated with the stigma are characteristic of all nettle flowers. They also appear very early in development. Combined this makes us think that they might have a role in pollination. Specifically in the reception of pollen. Being wind-pollinated, nettles don’t have a lot of control as to whose pollen reaches their female flowers and so there needs to be a way for them to control which pollen grains develop and fertilise the single egg. It seems likely that these hairs play a role and hopefully Jia will be able provide some more great images to test some hypotheses about this.

Female flower of Cecropia sp., a tcommon ropical tree from the Americas. In addition to stigma hairs you can see an apparent fold in the ovary. Image by Jia Dong, RBG Edinburgh.

Meeting Year 2, ‘Sapphire’ class at St Keyna’s primary school where I was asked several tricky questions

As part of my job I give talks to students or colleagues on aspects of my research and botany. Generally the less scientifically literate the audience the better and more insightful the questions. For this reason I was a little nervous and excited at meeting two classes at the St Keyna Primary School in Keynsham near Bath. I had been invited by my old friend Larissa Roberts who works at the school. After over 20 years working for a major museum I was also very honoured to be inaugurating their natural history museum! It might seem a poor use of resources for scientists to go and meet schoolchildren half way across the country and we struggled to find any resources to support for my visit. For me though it is very important. Botany is rarely taught in UK schools, there is no university degree in Botany in the UK anymore (imagine if that was the case for zoology or paleontology) and so the routes for recruiting young enthusiastic people from a variety of backgrounds into botany are somewhat limited. If visits such as mine inspire just one pupil to consider a career in botany then it would have a tremendous impact on our discipline.

Me, inaugurating the St Keyna Natural History Museum. A great collection of tarantula moults, birds nests and rocks! I should really have tucked my shirt in.

Some of the questions were quite a challenge. Mainly because although I should have I had not thought about them before. I was almost thrown by questions such as, ‘what is the rarest plant that you have collected?’, ‘what is the oldest plant that you have collected?’ and ‘how many new species have you discovered?’. On the basis of my answers I am not sure how well I would fair in a job interview. I was very pleasantly surprised to meet so many children with a spontaneous enthusiasm and interest in natural history and plants! I was also very impressed with how friendly and polite the children (and staff) were and of how well supported learning seemed to be at St Keyna’s. So all in all a very positive experience that I would gladly repeat.

Motacusal community members finishing the pollarding of their plot. Although ready to pollard since October there have been delays due to El Niño and the Brazil Nut harvest

Two years after planting our first plot at Motacusal, the community has just completed the first pollarding. The dense canopy of Inga trees has been reduced to a green mulch and the main stems taken away to be stored for fuel wood leaving about 1/3 ha of fertile ground for growing annual crops such as maize, rice or beans. The pollarding is the culmination of over two years work and testimony to the skills and hard work of our field team, lead by Forest Engineer, Rolman Velarde. We will leave the mulch to rot down a little and in a month the first crops will be sown.

Once the main stems have been cut, the smaller branches, twigs and leaves are left in the plot as mulch, providing much needed organic matter for the soil. Image: Rolman Velarde (Herencia)

Management of the Motacusal plot is being overseen by the communitie’s children through the ‘Bosque de los Ninos‘ programme which means that they get to choose what will be sown. This is not just important for the engagement of children but also for the community as a whole, linking our demonstration / trial plots with their most valued resource and bringing it to fruition is a powerful symbol. The children have been experimenting with growing various seeds for planting as part of the ‘productive’ part of their school curriculum and I am keen to see what has been planted in a month’s time. There stil remain some challenges though. The anomalous weather associated with El Niño could lead to the crops failing or to the pollarded Inga not recovering as planned.

Rolman Velarde explaining to the other participating communities how to pollard Inga trees for alley cropping. Image: Victor Soruco, Herencia.

We used the opportunity of this being the first plot to be pollarded to invite representatives from the other particpating communities: Palacios, San José, Jerico and Monte Sinai. This enabled us to train them in pollarding but also for them to get an idea as to what their agroforest plots will look like in a year or so.